Hydropower will (a) save the planet, or (b) destroy it. Choose one. Or maybe you shouldn’t. The ongoing debate over the role of hydropower reveals remarkable schisms in priorities and values among otherwise like-minded, environmentally enlightened folks. For my take on the issue, read on.

On First Glance

In the desperate fight to contain climate change before it overwhelms us, some environmentalists have had second thoughts about their age-old antipathy toward hydroelectric dams. Yes, dams famously destroy rivers and valleys, obliterate wildlife habitat and displace entire populations – frequently indigenous peoples with no place to go. But they’re carbon-free, right? If the world is going to get to “net-zero” emissions by 2050, the goal set in the 2015 Paris Agreement, we will need a diverse portfolio of renewable energy sources, even those that bring more than their share of collateral damage.

Not so fast, say other conservationists; hydroelectricity can hardly be considered green at all. Along with destroying vast habitat, dams require enormous quantities of concrete and steel to construct, themselves major contributors to carbon emissions. Worse yet, it turns out that the reservoirs behind hydroelectric dams in the tropics emit significant amounts of methane (think swamp gas), which is 21 times more potent a greenhouse gas than CO₂.

The battle over hydropower looks quite different in the United States than in much of the rest of the world because there are no large dams in the works in the lower 48 and just one advancing in Alaska. With no new construction to oppose, anti-dammers have focused on removal. They have been quite successful; according to American Rivers, an environmental advocacy group, 1,199 dams have been removed in the United States since 1999. The year with the most dam removals was 2018, with 99 removed, followed closely by 2017, with 91. Most of these dams, it should be noted, were small and did not contain hydroelectric turbines. But the movement’s greatest success story to date was the elimination of two huge dams on the Elwha River in western Washington State in 2011, both of which were still producing electricity.

Efforts continue to remove power dams on the lower Snake River (a tributary of the Columbia River) – the one immortalized in Woody Guthrie’s song about the Grand Coolie Dam. Guthrie’s song was “Roll On Columbia.” Like the Elwha dams, the Snake River dams are implicated in the decimation of the local Chinook salmon population. Chinook are vital to parts of the economy of the Pacific Northwest, not to mention to the culture of indigenous people – and the only food of the regional Orca population, which had dwindled to just 73 animals as of August 2019. The litigation surrounding these dams is now in its third decade.

Hence the dichotomy is stark. Construction of new hydroelectric dams has halted and even reversed in the United States, while construction continues across Europe and is even more evident in the developing world. The mega-dam projects under way outside Europe are often championed by the construction arms of large multinational corporations and the foreign bondholders who put up the cash to build them. Payoffs to corrupt regimes, staggering debts bequeathed to national governments and wholesale habitat devastation are just costs of doing business.

How It Works

Hydroelectric dams date to the 19th century. As the U.S. Geological Survey explains, “hydroelectric and coal-fired power plants produce electricity in a similar way. In both cases a power source is used to turn a propeller-like piece called a turbine, which then turns a metal shaft.”

The shaft moves a set of magnets past a set of conductors, causing electricity to flow – a phenomenon first identified by the great British physicist and chemist Michael Faraday. The difference between them: a coal plant burns carbon to heat water to produce steam, which spins the turbine, while a hydro dam uses falling water.

For that reason, hydroelectric dams are most commonly built on high-volume rivers at places with large drops in elevation – which is why they are more common in the Pacific Northwest than in Kansas. Most major dams include a reservoir, which stores water and allows the flow of water (and thus electricity) to be increased or decreased to meet demand. “Pumped-storage” hybrid systems use a reservoir in tandem with another power source, which can be any source of electricity available from the grid – increasingly solar and wind. The reservoir serves as a battery, storing energy in the form of water at the top of a dam when electricity demand is low and releasing it during daily and seasonal peak periods. Run-of-the-river dams do without the reservoir, producing electricity only when the river flows and providing no storage capacity. Large dams have multiple turbine- generator units: the Hoover Dam on the Colorado River has 17 units, while the gigantic Three Gorges dam on the Yangtze has 26 units capable of producing an astonishing 11 times as much power as the Hoover.

Worldwide, hydro accounts for about 17 percent of electricity production, with China the largest producer, followed by Canada, Brazil and the United States. Until recently, hydro was the largest renewable power source in the United States, in 2017 accounting for 7.4 percent of all the electricity generated by utilities. It was passed last year by wind, but is still a far larger source than solar, geothermal or biomass.

Yet, while renewable energy production will almost certainly continue to grow and could reach as much as 70 percent of the electricity market within decades, hydro isn’t likely to go much further in the United States. Modest gains in output may come from increasing the efficiency of turbines in place and by adding turbines to existing unpowered dams. “We’re still getting two-thirds of our capacity from coal and natural gas,” explains Steve Clemmer, director of energy research and analysis for the Union of Concerned Scientists, “so we need to do something. In the overall scheme of things, existing hydro still has an important role to play.” He notes that Canada produces a great deal of hydropower and that New England is willing to buy its surplus.

Taking Them Out

In the view of conservationists, there is something special about dams, something – as conservation problems go – that is disproportionately and metaphysically sinister. The outermost circle of the Devil’s world seems to be a moat filled mainly with DDT. Next to it is a moat of burning gasoline. Within that is a ring of pinheads each covered with a million people – and so on past phalanxed bulldozers and bicuspid chain saws into the absolute epicenter of Hell on earth, where stands a dam.

—John McPhee (1971)

McPhee was writing about David Brower, who resigned as president of the Sierra Club to start the more militant Friends of the Earth in 1969. He went on to found a number of environmental organizations before his death in 2000, and many of his acolytes have pursued dam removal. Hydroelectric dams tend to be among the largest and the most entrenched enterprises in local economies, providing jobs and cheap power. So efforts to remove them encounter greater resistance.

Many of these dams are privately owned, and whether the dams are still productive or not, their owners are typically loath to remove them. But privately owned dams must be licensed, and when those licenses come up for renewal, there is an opportunity for environmental groups, Native American tribes and others to seek modifications or mitigation

From the 19th century until the 1960s, the period in which most U.S. dams were built, “the approach was exploitation of the resource, not how it would impact fish or the drinkability of your water, or access to public resources,” says Kelly Catlett, an attorney with the Hydropower Reform Coalition. “You had these very broad initial licenses that let energy companies do whatever they wanted. We saw projects that would use all the water behind the dam when generating the most power, sending a lot of water downriver, creating a flood. A couple of hours later when demand goes down, you shut down and essentially created a drought. So the environmental community saw a strong need to get involved.”

Environmentalists scored a big win in November 1997, when the Edwards Dam on the Kennebec River in Maine became the first to have its owners’ license renewal application refused by the Federal Energy Regulatory Commission (FERC). Built in 1837, Edwards supplied electricity primarily to paper mills; between the dam’s blockage of spawning grounds and the mills’ effluent, local fish populations, including Atlantic salmon, river herring, striped bass and sturgeon, had fallen sharply. A 1986 federal law requires FERC to balance the environmental impact of a dam against the value of the electricity it produces. FERC decided Edwards failed the test and ordered that its owners remove the dam or spend $8.9 million on a fishway and another $1 million on environmental remediation. Since the dam’s removal, the fish have returned.

In 2011, the Elwha River in northwestern Washington State became the site of the largest dam removal in American history. In her 2013 book, Elwha, A River Reborn, reporter Lynda Mapes tells the story of how the initial dam was built in 1910 with no permit and without even the minimal environmental mitigation, required by the laws of the day, of including a fish ladder. Located just five miles from the river mouth, the Elwha Dam blocked 93 percent of spawning habitat for ocean-going fish. A larger dam upriver, the Glines Canyon Dam, was built in 1926, this time with a permit but again without a fish ladder. Washington’s state fish commissioner allowed the dam builder to donate land for a hatchery instead. But the hatchery soon failed, and the state did not pursue the matter.

With the “Niagara of the Pacific” producing huge amounts of cheap power, nearby Port Angeles became a boom town. The Elwha River dams, along with the timber, paper and pulp mills they supported, were celebrated by all except the indigenous people who saw their burial grounds desecrated and the obliteration of the salmon runs that had long been their livelihood. Elders spoke of salmon so prodigious a person could walk across the river on their backs. Some of the fish weighed over 100 pounds each. In 2010, only 500 fish came back to the river to spawn, a record low.

But the expiration of the dam’s license gave the Lower Elwha Klallam tribe an opening. Between 1986 and 1988, the tribe joined forces with environmental groups, including the Seattle Audubon Society, Friends of the Earth, the Sierra Club and Olympic Park Associates, to fight relicensing. Their cause was aided by a court ruling that denied FERC jurisdiction because the Elwha passes through a national park.

President George H.W. Bush filled the regulatory void, authorizing removal of the dam when he signed the Elwha River Ecosystem and Fisheries Restoration Act of 1992. But removal was bitterly opposed by industry groups, who labeled the effort “a virgin Earth” cult; the dams survived another 20 years.

Today the Elwha teems with fish. But the battle is being refought on the lower Snake River, which passes through Idaho and Washington, again pitting dam advocates against a consortium of tribal and environmental groups. Unlike the Elwha dams, which were owned and operated privately, the Snake dams are federal and thus not subject to relicensing. Just this past February, a draft federal report rejected requests for dam removal for the sixth time. The report conceded that dam removal would “provide a long-term benefit to species that spawn or rear in the mainstream Snake River habitats” but would also have adverse impacts on power costs and reduced reliability of the electrical grid.

“Essentially they asked the fox guarding the henhouse to provide an analysis whether said fox was the right one to guard the henhouse,” says Anthony Jones, principal of Rocky Mountain Econometrics, in Boise. “To no one’s surprise, the fox concluded it was doing a great job.”

A 30-year veteran of the electrical industry, Jones says that fierce competition from burThird Quarter 2020 11 john gussman geoning solar power means that the Bonneville Power Administration, the federal agency that operates the dams, is now operating at a disadvantage. “BPA generates about half the power in the Pacific Northwest, but they export about a third of that to California. Prior to 2009, they got $60 to $70 a megawatt, so the more surplus they created the better,” he says.

“But in 2009, solar in California started hitting critical mass. Prices dropped to the teens and sometimes went negative,” as power producers unable to shut down capacity paid utilities to take it off their hands, he explains.

Elsewhere, though, privately owned dams that no longer pencil out are being removed. The Klamath River Renewal Corporation has contracted to remove four dams on the Klamath River that are owned and operated by PacificCorp, a unit of Warren Buffet’s Berkshire Hathaway Energy conglomerate. The Klamath River runs through southern Oregon and northern California.

“Where hydropower is able to adapt and respond and provide resilience in the grid, that is a value that should be compensated,” says Catlett of Hydropower Reform. “Where projects are not able to do that, we need to seriously consider removing them.”

Finding Common Ground

That’s not the whole story, however. Some longtime dam opponents say climate change is so dire a threat that they are coming to terms with hydropower. “The irony is you have this very large source of energy that is both a solution to climate change and an environmental problem,” says Dan Reicher, the executive director of the Steyer-Taylor Center for Energy Policy and Finance at Stanford University.

Reicher was an assistant secretary of energy in the Clinton administration and is on the board of the advocacy group, American Rivers. With these credentials, Reicher has been able to bring hydro industry leaders and environmental groups together to seek common ground. “There are several things the industry can do to advance U.S. hydropower and address climate change,” he says, including refitting existing powered dams with more efficient turbines, which could increase lowcarbon electricity output 20 to 30 percent; powering non-powered dams; and building pumped storage. Closed-loop pumped storage, a newer technology, is built off the river, so the environmental impacts are much reduced compared to existing facilities.

“There has long been a place for environmental groups and the energy industry to come together,” Reicher adds. For example, hydroelectricity dams are such a big source of “storage capacity that the wind and solar industries are interested in seeing this happen as well.”

Halting New Construction

Outside the United States, environmentalists and indigenous groups have in some cases aligned to block new construction, which can otherwise seem an unstoppable juggernaut. Consider Laotian leaders’ ambitions, egged on by China, to become the “battery of Asia,” despite cataclysmic side effects – such as one dam failure that killed some 800 people. A few particularly ill-considered projects have been sidelined, like the Grand Inga in the Republic of Congo, which, at a proposed 39,000 megawatts, would have been the largest hydro project in the world. Its future has been on hold since the Spanish firm ACS Group dropped out in January 2020, leaving the project to ACS’s Chinese and German partners.

In Chile, meanwhile, HidroAysén, a megaproject to build five hydroelectric dams, two on the Baker River and three on the Pascua River, has hit a wall of popular opposition. HidroAysén was a joint venture between Endesa, a subsidiary of the Italian conglomerate ENEL, and Colbun, a Chilean utility company. “When the dams were approved in 2011, there were huge protests in the streets almost weekly,” says Amanda Maxwell, Latin America Project Director for the Natural Resources Defense Council, which joined a coalition of Chilean NGOs in fighting the project. “This was the predecessor to the student protests, the first time people united together and got out in the streets.”

Some South America countries “tout their huge renewable portfolios, and that’s largely due to large hydro,” acknowledges Maxwell. “But due to climate change, we can no longer rely on precipitation. You have El Niño, La Niña, drought. The idea that hydroelectric dams are a stable source of electricity is not accurate.”

Hydro and the Resource Curse

When economists speak of a “resource curse,” they are usually referring to petroleum and natural gas, resources that one would assume would drive prosperity, but sometimes perversely impede growth by increasing corruption and crowding out industries needed for balanced development. Kathleen Hancock, a political scientist at the Colorado School of Mines, wonders if the same forces are at work with hydropower. “There’s a tendency for people to think renewables are wonderful,” she says, “but they’re more complex than that, and large hydro still more so.”

Hydroelectric dams supply at least 50 percent of electricity in more than 60 countries and more than 90 percent in some 20 countries, Hancock notes. In states as diverse as Bhutan, Norway, Paraguay, and several African countries, essentially all commercial electricity comes from hydro. But too often, there are negative side effects ranging from unstable energy supply (as pointed out above, it’s gotta rain) to “enclave economics,” where the benefits all go to foreign investors and big industries rather than the local economy.

Enclave economics were evident in the 2,400-megawatt Bakun Hydroelectric Project on the island of Borneo in Malaysia, which started operating in 2011. Construction created boom-and-bust cycles, inflationary pressures and shortages. The electricity from the completed project went primarily to power smelters rather than to the local population, and the project offered no permanent jobs or skills training to the villagers it displaced.

The 2,700-megawatt Yacyretá Dam between Argentina and Paraguay, which generates about half of all the electricity consumed by both countries, is an example of what economists call “rent seeking” — in this case, a polite term for allowing builders and government officials to skim off the cream. Hancock and her co-author explain that the cost of the project, originally expected to be $1.5 billion, ballooned to $15 billion, primarily due to financial shenanigans. The consortium that won the contract for the dam, led by French and Italian firms, was accused of disbursing hundreds of millions of dollars in bribes. Much of the paltry $27 million intended to compensate villagers for relocation was instead funneled to contractors and assorted interests.

Then there’s the issue of unstable generation capacity. Water levels behind the dam vary with the seasons, but are also subject to longer-term trends driven by climate change. In the Democratic Republic of the Congo, where hydropower supplies more than 99 percent of electricity, supply has been erratic, often fluctuating by double-digit percentages.

Consider, too, that waters rich in minerals or with high levels of chemicals from agricultural runoff can corrode the turbines, while debris from logging and deforestation can increase silt.

“The hydroelectric curse is not a given,” Hancock says. “It depends on the government and institutions.” And too much of the investment in hydro is in huge dams. “If you took all this money going to mega-dam projects and instead put it toward micro-hydro, wind and solar, you could do as much. The World Bank stopped funding big dams because of the corruption, but went back to funding them because Africa is so behind on electricity,” she says. “The feeling was we just have to live with this.”

Other researchers say that large dams often exacerbate the very problems they were intended to solve — or create new ones. The world has spent an estimated $2 trillion on dams in recent decades to supply water for irrigation and burgeoning cities, or to generate hydroelectricity. But as Ted Veldkamp, at the Institute for Environmental Studies at Vrije Universiteit Amsterdam, told New Scientist, that activity has left 23 percent of the global population with less water, compared with only 20 percent who have gained. “Water scarcity is rapidly increasing in many regions,” she said. “Building more dams might mitigate tomorrow’s climate change impacts for a certain group while putting others under pressure today.”

Veldkamp’s research included the Yellow River in arid northern China; the Ganges, where upstream activity in India has damaged livelihoods in downstream Bangladesh; the Euphrates, where Turkish dams cause drought in Iraq; and the Colorado River, where U.S. withdrawals leave little water for Mexico. A 2019 study, which claimed to be Europe’s first inventory of hydropower, found that 8,507 new plants are planned for the coming years, adding to the 21,387 already on the continent. A further 278 plants are under construction. The dams are part of a so-called European green deal whose goal is reducing greenhouse emissions to net-zero by 2050.

“We must understand that the already high demand for water resources, especially in southern Europe, will be exacerbated by such large-scale hydropower exploitation,” Steven Weiss of the Karl-Franzens University of Graz told the Guardian.

Mitigate, Don’t Eliminate

Despite hydroelectric dams’ well-documented problems, the fact remains they provide more renewable energy than any other source. The Intergovernmental Panel on Climate Change concluded that “the significant increase in hydropower capacity over the last 10 years is anticipated in many scenarios to continue in the near-term (2020) and medium-term (2030), with various environmental and social concerns representing perhaps the largest challenges to continued deployment if not carefully managed.”

That scenario has prompted some longtime dam foes to seek a middle ground. American Rivers partnered with the Center for Resource Solutions to create the Low Impact Hydropower Institute, which rates dams according to a variety of environmental and cultural criteria.

Passing the test — 167 have made the cut thus far — gives dam owners a leg up in selling their power to utilities that are under pressure to go greener. “You can include hydro in a renewable portfolio while also insisting that they respect the environment,” concludes Shannon Ames, the institute’s executive director. “They’re not mutually exclusive.”

• • •

In any event, opponents of hydro sometimes err by forgetting that the best can be the enemy of the good. Benjamin Sovacool of Sussex University, who is the lead author of the Intergovernmental Panel on Climate Change’s next Assessment Report, notes that all electricity generation technologies have negative externalities. “Coal and oil are the ‘worst,’ solar and wind the ‘best,’” Sovacool says. But these rankings reflect priorities as well as location and the different technologies’ inherent characteristics. “You can make dams that are very low impact, very low carbon, as gentle as hiking, in theory. Dams are neither good nor bad, it’s how they’re designed and run. It’s as much about governance and policy as technology.”